According to the release of smart phones, positioning information service which was available in an environment allowing use of a PC or a notebook computer has been developed and thus enables a user to easily search for a position of the user and information on a neighboring area anytime and anywhere. Google uses satellite images, and a portal site including a domestic portal site, such as Daum, uses aerial photographs for a map service and also provides a service enabling a user to look around a street by using panorama images. In the meantime, Microsoft disclosed the Photosynth service in which pictures shared through the Internet are searched and collected and a photography position, a photography direction, and 3D coordinates of a main feature point of each image are calculated, so that the collected pictures are not displayed in a form of a thumbnail view in which the collected pictures are simply arranged, but a user can view the collected images as if the user actually navigates the place of the collected pictures. Several universities have conducted research for producing a 3D model, as well as 3D coordinates of the feature point, by expanding the Photosynth service. Google provides a 3D map service by uploading a 3D model modeled using a 3D modeling tool, such as Google Sketchup, and collects 3D data of an actual street by using a 3D scanner. As described above, various methods have been attempted in order to expand an existing map service using an image to a 3D map service.
A conventional method of producing a 3D model having a static background includes a manual operation using computer graphics software, an image-based modeling method using multiple images, etc.
A method of producing a 3D model by using computer graphics professional software, such as Maya and 3D Max, by a skillful designer may produce a detailed model by using various functions provided in the software. However, the method has disadvantages in that a quality of a 3D model and a time for producing a 3D model may be different depending on the ability of a designer and there is no method of securing geometrical accuracy with an object, such as an actually existing building.
The image-based modeling method using multiple images calculates a camera matrix and 3D coordinates of a feature point by performing camera self-calibration using corresponding points between many images, like the Photosynth. In this case, because the calculated 3D coordinates are not dense, the image-based modeling method may produce a 3D mesh by densely spreading 3D points with the points as an initial value or may manually model a 3D mesh through a user's interaction by using a camera matrix. The image-based modeling method may produce a relatively geometrically accurate 3D model compared to a model manually produced using computer graphics software, and may produce a realistic model because it is possible to extract a texture from an image. However, the image-based modeling method has a problem in that the accuracy of a model is dependent on image resolution.